Network security appliance



FIG. 1 is a front perspective view of a network security appliance;

FIG. 2 is a top view of the network security appliance of FIG. 1;

FIG. 3 is a bottom view of the network security appliance of FIG. 1;

FIG. 4 is a right side view of the network security appliance of FIG. 1;

FIG. 5 is a left side view of the network security appliance of FIG. 1;

FIG. 6 is a front view of the network security appliance of FIG. 1; and,

FIG. 7 is a rear view of the network security appliance of FIG. 1.

The broken lines in the drawings depict portions of the network security appliance that form no part of the claimed design. 

CLAIM The ornamental design for a network security device, as shown and described. 